Patent US4491391A successfully refreshed from Google Patents.
US4491391A
Expired / Lapsed
US
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Liquid crystal display device with visibly imperceptable spacers
Assignee: Mannesmann VDO AG
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Filing: 1982-02-16
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Granted: 1985-01-01
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Expires: 2002-02-16
Abstract
Abstract A display device for displaying light characters against a dark background, particularly a liquid-crystal display. It has a fluid which can be switched between two optically different states located between two support plates (1, 2) which are parallel to each other. On one of the facing surfaces of the support plates there is applied an insulating layer of fixer which contains the spacer elements (7). The support plates (1, 2) are maintained at a given distance from each other by these spacers (7). Furthermore, a polarizer (11, 12) is associated with each support plate (1, 2). In order to assure a strong contrast between the character and its background with precise maintenance of the distance between the support plates (1, 2), the insulating layer of fixer completely covers the support plate (1) and the spacer elements (7) consist of a material of dark color.
Inventors
- 👤 Friedrich W. Nickol
- 👤 Harald Perthes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:23
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1339; G02F1/13392
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
174 words
In a liquid crystal display device having light characters against a dark background, said device having a fluid which can be switched between two optically different states and is arranged between two support plates which are parallel to each other with a fixing layer applied to one of the facing surfaces of the support plates, wherein said fixing layer is an insulating layer containing spacer elements by which the support plates are held at a given distance apart from each other, and with a polarizer associated with each support plate, the improvement wherein the insulating layer substantially completely covers the corresponding said support plate, and the spacer elements comprise a light absorbing material of dark color, and wherein said spacer elements have a diameter less than 100 microns and are spaced apart from each other with spacings greater than said diameter with a distribution density less than two spacer elements per square millimeter thereby minimizing the diffusion of light on the dark background while being substantially imperceptible to a viewer of the display device.
Claim 2
Dependent Claim
174 words
In a liquid crystal display device having light characters against a dark background, said device having a fluid which can be switched between two optically different states and is arranged between two support plates which are parallel to each other with a fixing layer applied to one of the facing surfaces of the support plates, wherein said fixing layer is an insulating layer containing spacer elements by which the support plates are held at a given distance apart from each other, and with a polarizer associated with each support plate, the improvement wherein the insulating layer substantially completely covers the corresponding said support plate, and the spacer elements comprise a light absorbing material of dark color, and wherein said spacer elements have a diameter less than 100 microns and are spaced apart from each other with spacings greater than said diameter with a distribution density less than two spacer elements per square millimeter thereby minimizing the diffusion of light on the dark background while being substantially imperceptible to a viewer of the display device.
Claim 3
Dependent Claim
23 words
The device according to claim 1, wherein the spacer elements are disposed at a distance apart from each other greater than their diameter.
Claim 4
Dependent Claim
41 words
The device according to claim 2, wherein the spacer elements have a diameter of less than 100 μm and are arranged on the corresponding support plate with a distribution at most equal to one to two spacer elements per square millimeter.
Claim 5
Dependent Claim
12 words
The device according to claim 1, wherein said spacer elements are spherical.
Claim 6
Dependent Claim
14 words
The device according to claim 1, wherein said spacer elements are made of glass.
Claim 7
Dependent Claim
22 words
The device according to claim 1, further comprising a surface electrode contiguous to said insulating layer and covering said corresponding support plate.
Claim 8
Dependent Claim
29 words
The device according to claim 1, further comprising electrodes arranged on each of said support plates, and wherein said insulating layer completely covers the electrodes and the support plates.
Claim 9
Dependent Claim
22 words
The device according to claim 1, further wherein said insulating layer is an anti-reflection layer which completely covers said corresponding support plate.
Claim 10
Dependent Claim
22 words
The device according to claim 1, further wherein said insulating layer is an orientation layer which completely covers said corresponding support plate.
Claim 11
Dependent Claim
37 words
The device according to claim 1, in which an electrode comprising separately controllable electrode segments is arranged on said corresponding support plate, and wherein the insulating layer is formed with recesses which correspond to said electrode segments.
Claim 12
Dependent Claim
16 words
The device according to claim 1, wherein the insulating layer completely covers the corresponding support plate.
Claim 13
Dependent Claim
112 words
In a liquid crystal display device having light characters against a dark background, the device having two spaced-apart support plates, and an electrode structure supported thereon, the combination comprising: spacers of a dark, light absorbing material; and a layer of optically transmissive material fixedly supporting said spacers relative to one of said support plates, and wherein said spacer elements have a diameter less than 100 microns and are spaced apart from each other with spacings greater than said diameter with a distribution density less than two spacer elements per square millimeter thereby minimizing the diffusion of light on the dark background while being substantially imperceptible to a viewer of the display device.
Claim 14
Dependent Claim
112 words
In a liquid crystal display device having light characters against a dark background, the device having two spaced-apart support plates, and an electrode structure supported thereon, the combination comprising: spacers of a dark, light absorbing material; and a layer of optically transmissive material fixedly supporting said spacers relative to one of said support plates, and wherein said spacer elements have a diameter less than 100 microns and are spaced apart from each other with spacings greater than said diameter with a distribution density less than two spacer elements per square millimeter thereby minimizing the diffusion of light on the dark background while being substantially imperceptible to a viewer of the display device.
Claim 15
Dependent Claim
13 words
A device according to claim 12 wherein said layer encloses said electrode structure.
Claim 16
Dependent Claim
17 words
A device according to claim 13 further comprising polarizers disposed on outer surfaces of said support plates.
Claim 17
Dependent Claim
16 words
A device according to claim 12 or 13 wherein said spacers are light absorbing glass beads.
Claim 18
Dependent Claim
16 words
A device according to claim 12 or 13 wherein said spacers are light absorbing glass rods.
Claim 19
Dependent Claim
25 words
A device according to claim 11 wherein said spacers have a bead-like shape, and said layer includes recesses corresponding to segments of said electrode structure.
References Cited (Backward Citations)
US3840695A
Cited
US4249800A
Cited
US4231034A
Cited
US4248502A
Cited
JPS5525035A
Cited
US4341445A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-01 | 1988-07-02 | 1989-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-01 | 1992-07-02 | 1993-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-01 | 1996-07-02 | 1997-01-01 | $7700.00 | Window Closed / Lapsed |